Jacobs' grandfather, Peter Jacobs, of Redding, said his grandson was killed in an explosion last week.

Sean Jacobs' parents, Robert and Jacquelyn Jacobs, of Redding, flew to Dover Air Force Base in Delaware last week to identify their son's body. They had not returned by Sunday night, Peter Jacobs said.

Sean Jacobs, 23, graduated in 2006 from Foothill High School in Palo Cedro, where he was active in athletics, his grandfather said Sunday. He was nominated to attend the U.S. Military Academy at West Point, where he graduated in May 2010.

"He was an All-American boy," Peter Jacobs said. "He was a winner all the way, and he had a great future."

Peter Jacobs was a naval officer during World War II and administered the oath of office to his grandson during his graduation. His parents also attended his graduation. After graduating from West Point, Sean Jacobs spent two years assigned to Fort Lewis, Wash. He was sent to Afghanistan this year, his grandfather said.

The circumstances surrounding his grandson's death were unclear, but it appeared to be combat-related, Peter Jacobs said.

Our sincere and deepest condolensces to the Jacobs family for your loss. There clearly are no words to say upon losing a fine young man like Sean, except to say that my family and I have you in our thoughts and prayers.